Presently, both the power of motor and the outflow aperture of the submersible sewage pump is poor, that is to say, the power is generally less than 400 kw and the outflow aperture is generally below 800 mm. Such submersible sewage pump is assembled in a conventional suspension way, that is to say, the side of the submersible sewage pump is fixed on one side of the elbow base at the bottom of the pool by means of a suspension unit, and thus the bottom of the pump is suspended with the bottom of the pool. However, the whole weight of a large-scale submersible sewage pump, is which generally means the submersible sewage pump with the powder more than 400 kw and the outflow aperture more than 800 mm, is larger, which is generally more than 10 t. When such large-scale submersible sewage pump is fixed on a side of the seat in a suspension way in the prior art, there are several disadvantages as follow:    1) The installation in a lateral suspension way certainly brings about increasing lateral torque to the seat, and the suspension unit is usually cast by the cast iron. The increasing volume and weight of the submersible sewage pump certainly will cause the inadequate strength of the suspension unit, and it leads the suspension unit to break, so that the whole submersible sewage pump can not work.    2) Because the bottom of the submersible sewage pump is suspending, shock caused by such a pump when working is increased, and thus it certainly will affect the normal running of the pump and there will be huge potential safe hazard.